drm/amd/pm: only send GmiPwrDnControl msg on master die (v3)

PMFW only returns 0 on master die and sends NACK back on other dies for
the message.

v2: only send GmiPwrDnControl msg on master die instead of all
dies.
v3: remove the pointer check for get_socket_id and get_die_id as they
should be present on Aldebaran.

Signed-off-by: Tao Zhou <tao.zhou1@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>